Glissa, Herald of Predation, Breath of Fury, and Concordant Crossroads

Prerequisites

• Glissa, Herald of Predation on the battlefield
• Breath of Fury on the battlefield
• Concordant Crossroads on the battlefield
• Breath of Fury attached to another creature you control
• You control at least one additional creature
• An opponent cannot block and kill creatures you control

Steps

1. At the beginning of your combat phase, Glissa triggers, creating two Incubator artifact tokens with two +1/+1 counters on them
2. Deal combat damage to an opponent using the creature with Breath of Fury attached
3. Breath of Fury triggers, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to another creature you control, then causing you to untap all creatures you control and to get an additional combat phase after this one
4. At the beginning of your next combat phase, Glissa triggers, transforming all Incubators you control into 0/0 Phyrexian artifact creatures
5. Repeat steps 2 and 3 one additional time
6. Repeat from step 1

Results

• Infinite combat damage
• Infinite combat phases
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite sacrifice triggers
• Infinite untap of creatures you control